交流的磁铁，移动电话的磁铁

Sintered NdFeB magnets are a type of rare earth alloy with typical atomic structure of Nd2Fe14B which stands for 2 atoms of Neodymium, 14 atoms of Iron(Fe) and one atom of Boron. There are some other elements that may be used for purposes of improving the coercivity, gaining lower weight loss and other special characteristics. The sintered Neodymium Iron Boron magnet has higher magnetic properties compare to Samarium Cobalt magnets, however it is more easily oxidized and generally does not have the same temperature resistance. The highest energy products for NdFeB could reach 50 MGOe commercially or more. These materials are only used in very selective applications due to the cost. Cost is also driven by existing intellectual property rights of the developer of this type of magnets. Their high energy products lend themselves to compact designs that result in innovative applications and lower manufacturing costs. NdFeB magnets are highly corrosive, so that various surface treatments include nickel, Zinc and gold plating as well as epoxy resin coating.